Enchiridion — Privacy Policy

Last updated: 25 September 2026

Enchiridion ("we", "us") provides an offline-first clinical companion app with textbooks, calculators, instrumentation guides, OSCE stations, and exam preparation with spaced repetition. This policy explains what personal data we collect, why, and the choices you have. Contact: support@enchiridion.site.

1. Data we collect

Account data. When you register: email address, password (stored only as a one-way hash by our authentication provider — we cannot see it), display name, and role (student, clinician, or other). If you add a profile photo, the image is stored in our file storage and served through a public link tied to your account.

Device data. To enforce one account per device, the app records a device identifier (on Android, the platform device ID; on iPhone and other platforms, a randomly generated ID stored securely on your device), the date the device was bound, and a history of previously authorised devices with their authorisation dates.

Study data. Your answers, per-question review progress (attempts, lapses, due dates), daily statistics (questions answered, correct answers, performance points), and module/exam-prep progress. This is stored on your device first and synced to your account when you are signed in, so it follows you across devices.

Entitlements and payments. Which Premium access you hold, its start and expiry dates, and how it was granted. Website payments are processed by Flutterwave and in-app payments by Google Play; we never see or store your card number, bank details, or USSD PIN. We keep the payment reference (Flutterwave transaction ID or Google Play order ID and purchase token), plan, amount, currency, and verification result so we can verify purchases, prevent one purchase being used by two accounts, and avoid double charges.

Subscription records. For a subscription we store the plan, provider, status, whether it renews, the current paid period, cancellation and refund dates, and an audit history of those changes, so the app and website can show when you will next be billed and how to cancel. Renewals are run by the provider you bought through.

Email preferences. Whether you asked to receive Enchiridion offers, when and where you gave or withdrew that consent, and your region if you told us. Account, security and billing emails are sent regardless of that choice.

Terms acceptance. The version of the Terms and Conditions you accepted at sign-up, and when — kept as our record that you agreed to them.

Support and content reports. Anything you send to support@enchiridion.site, and any question you flag in-app (question ID and reason).

Synced to your account. When you are signed in, the following sync to your account so a new device recovers everything: reading notes, pinned margin notes and their collections, text clips, bookmarks, per-question answers, reading settings (theme, font), recently opened books, review progress, and daily statistics. Sync is last-write-wins per item, and deletions propagate to your other devices (deletion records are kept for 90 days, then purged).

Stored on your device only. Question-rotation state, reading position, and the subscription check timestamp. These never leave your device.

What we do not collect. No advertising identifiers, no location data, no analytics or crash-reporting SDKs, no contact lists. Study-buddy reminders are scheduled and delivered entirely on your device.

2. Why we use your data (lawful bases, NDPA 2023)

Contract — to create your account, sync your study progress, unlock content you paid for, and run the leaderboard.
Legitimate interests — to keep accounts secure (one-device binding, fraud and replay prevention on payments), maintain the service, and respond to support requests.
Consent — profile photo and any optional data you choose to provide. You may withdraw consent by deleting the photo or your account.

3. Who sees your data

You. Your study records and entitlements are visible only to you, protected by database access rules that isolate every account.
Other users — limited. The leaderboard shows display names and total points only (never email or device data). Your profile photo is served from a public storage link: anyone who obtains the link can view it.
Service providers (sub-processors).
Supabase — hosting, authentication (including sign-up codes and password-reset emails), database, and file storage.
Flutterwave — website payment processing (card/bank/USSD), in Nigerian naira (₦). Their own privacy terms apply to payment details.
Google Play — in-app subscription billing. Google's own privacy terms apply to payment details.
Authorities — only where required by Nigerian law.

We do not sell personal data and we do not share it for marketing.

4. How long we keep data

Account, study, and entitlement records are kept while your account is active. Payment references are kept for our financial records. If you delete your account, your profile, study records, and entitlements are removed (see §6). Device-only data is erased when you uninstall the app or clear its data.

5. Security

transport encryption on all connections; database access rules that confine each user to their own rows; server-side verification of every payment before access is granted (the app cannot grant itself access); and single-device binding with a 30-day cooldown on device switches. No method is foolproof — report suspected breaches to support@enchiridion.site and we will act, including notifying the Nigeria Data Protection Commission and affected users where the law requires it.

6. Your rights

Under the Nigeria Data Protection Act 2023 you may request, free of charge: a copy of your personal data; correction of inaccurate data; deletion of your data and account; restriction or objection to certain processing; and withdrawal of consent. Email support@enchiridion.site with the subject "Data request". We will verify you own the account and respond within the statutory timeframe.

To change your display name or photo, use the Profile screen in the app. To delete your account, contact support (in-app deletion is on our roadmap — see the compliance notes below).

7. Children

Enchiridion is intended for medical students and clinicians. If you are under 18, use the app only with a parent's or guardian's permission. If we learn we hold a young child's data without proper consent, we will delete it.

8. Changes

Material changes will be announced in-app and on this page with a new "last updated" date. Continued use after changes take effect means you accept the updated policy.

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Implementation notes (not for publication)

Facts assumed above that must stay true: RLS isolates per-user rows; leaderboard RPCs return display-name + points only; avatars bucket is public-read; no analytics SDKs; notifications are local-only; payments are one-time website purchases in NGN verified server-side; user notes, bookmarks, clips, answers, settings, and history sync last-write-wins with 90-day deletion tombstones; support is email-only. Outstanding gaps are tracked in `docs/legal/ndpa-gap-review.md`.